1. Field of the Invention
The present invention related to a document camera which takes a visual image of a material (object or document) placed on a surface where the visual image is taken with a video camera, electrically converted to a digital image, and transmitted to an external display device.
2. Description of Related Art
Over-head projectors (OHP) are most popular visual presenters used in fields such as education and legal. With significant improvement of CCD (charge coupled device) and CMOS sensors, document cameras using the CCD or CMOS sensor have been developed and proposed. In such a document camera, a visual image of a material, a sample, or another subject matter placed on a table is taken with a CCD (or CMOS sensor) located above the table. The visual image is output as video signals to a display device, i.e., a computer monitor or a projector, etc.
A number of document camera are available in the market. However, many of the document cameras cannot capture a larger viewing area, e.g., an area greater than 8.5″ by 11.″ A large number of the document cameras cannot be folded into a convenient storage position.
In addition, document camera cannot receive wireless video input from an external device. Document cameras also do not have features that allow the reception of a television signal as an input signal. In addition, the document camera does not have capabilities of operating like a digital video recorder.